1. Field of the Invention
The present invention relates to the assembly of ductwork sections having channel flanges at their ends. More particularly, the invention relates to a method of assembly of such flanged ductwork sections utilizing a unique sealing bracket which quickly and efficiently seals the assembled ductwork sections such that air leaks are prevented.
2. Description of the Related Art
Presently, flanged ductwork sections which are formed with such channel flanges, are assembled by the placement of angle plates into the corners defined by the channel flanges positioned at the ends of the ductwork sections, as more particularly described in U.S. Pat. Nos. 5,283,944, 5,321,880 and 5,342,100 to Goodhue. The contents of U.S. Pat. Nos. 5,283,944, 5,321,880 and 5,342,100 are incorporated in their entirety by reference herein and made a part of this application.
More particularly, the Goodhue patents relate to angle plates for assembling such ductwork sections having transverse duct flanges by placement of the angle plate into an open space or “notch” in each corner of the duct, the notch being defined by the ends of the transversely oriented flanges of the ducts. Once the angled plates are fully seated in the ductwork flanges, the side edges of the ductwork flanges adjacent the notch are crimped into overlying relation with respect to the angle plate to create a channel so as to assure interlocking of the angle plates with the ducts.
In practice, the flanges can be structured and dimensioned to provide interlocking of the angle plate, without need for crimping the side edges of the flanges after placement of the angle plate.
After the angle plates are secured with respect to the ducts, a suitable sealant or gasket is applied to the flange surfaces and the ducts are secured together by bolts passing through each respective pair of face-to-face angle plates and tightened by nuts to provide an airtight seal.
In general, the assembly of the angle plates with the ductwork sections as described in the Goodhue patents is accomplished by automatic machine operations as described in the Goodhue patents.
More recently, U.S. Pat. No. 8,875,388, dated Nov. 4, 2014 relates to an apparatus and method for placement of such angle plates in transverse duct flanges of the type described in the Goodhue patents. Moreover, US Published Application No. US 2014/0319165, dated Oct. 30, 2014 relates to an apparatus and method for placement of such angle plates in transverse duct flanges, utilizing a package purportedly for use in the apparatus for automatically assembling the angle plates in the channel shaped flanges. The disclosures of U.S. Pat. No. 8,875,388 and Application Publication No. US 2014/0319165 are incorporated in their entirety herein by reference herein, and made a part of this application.
Disadvantages of the Current System of Assembling Flanged Ductwork Sections
One disadvantage of the present system of assembling such flanged ductwork sections relates to the presence of a notch between the edges of adjacent flanges, and an aperture in each of the corners of the ductwork section between adjacent flanges and adjacent the notch. In practice, the ductwork section is initially formed from a metal such as galvanized sheet steel, and is made into an elongated box-like member of one-piece or multiple-piece construction. The ductwork section will generally have a rectangular cross-section, and for most applications, a square cross-section. Such ductwork can also be made of galvanized steel, stainless steel, aluminum, or any other materials approved by local codes for heating, ventilating and air conditioning systems (hereinafter sometimes referred to as “HVAC” systems).
To create the flanges, a slit is introduced at each corner of the ductwork section, followed by bending of the marginal portions of the metal adjacent each slit. Since the slits may be made by manually applied cuts in the metal, they are not always identical. Accordingly, when the flanges are formed by bending the respective marginal portions adjacent each slit, the aforementioned notch is formed in the corner of the duct, and a small aperture is often formed where the flanges meet at the duct wall. Since this small aperture in the corners of the duct are potential sources of leaks of conditioned air, in order to avoid such loss of conditioned air, the apertures must be sealed.
The angle plate is positioned in contact with adjacent flanges and is progressively pressed into contact with the flanges. The marginal edge portions of the flanges extending outwardly of the legs of the angle plate are then crimped over the edge portions of the legs of the angle plate to create a channel which secures the angle plate in position with respect to the ductwork section.
The Sealing Step
Since sealing of the apertures must be accomplished with materials approved for heating, ventilating and air conditioning, the sealants usually applied to the apertures are generally of the type which require a relatively extensive curing time, sometimes up to approximately twenty-four hours. Therefore it can be readily appreciated that such twenty-four hour period provides a relatively significant delay in the production schedule of the ductwork sections.
I have invented a corner seal device which is quickly applied to each of the four corners of the ductwork assembly so as to extend across the notch between the orthogonal flanges, while at the same time, sealing the unwanted air leaks created by the duct forming slits, thereby resulting in improved efficiency for assembly and operation of such ductwork sections. My invention also relates to improvements in such ductwork, and an improved method of assembling such ductwork, which method is cost effective and which eliminates costly labor expenses. My invention therefore improves such air conditioning systems which incorporate such ductwork sections.